912ULS carb keeps overflowing
Hello all,
we have a brand new Rotax 912 ULS 100 hp in a used Flight Design CT.
Engine was installed in Winter.
Right after first time opening the fuel valve, one carb. overflowed. Before ever trying to crank the engine. Sent them in to Dealer and they fully cleaned and checked the carburetors. (there was some gunk inside both needles).
Installed again and was good for a few hours of flight time. Then same carb. spilled over again.
Uninstalled and taken apart by company. Some metall debris inside prevented needle from closing. So cleaned and inspected again and afterwards supposedly all is well.
One very brief flight afterwards was well. 2nd Flight had to aborted after 1 Minute - this time the other carburetor spilled...
We don't know the root cause this time, yet.
Anybody any ideas?
The CT has only the mechanical fuel pump. No additional electrical pump. High-wing gravity feeds. Several fuel filters: in the wings a coarse one, one filter near the shut-off valve and actually another one inside the gascolator. All clean.
Ran just fine for 1000+ hours on old engine on the same setup.
Besides the engine swap only fuel filters had been cleaned and all hoses been replaced.
Anybody having a remote idea what else could be causing this?
